The present invention relates to valves for fitting to pressurized receptacles.
French patent application FR-A-2 680 161 describes a valve for a pressurized receptacle that includes a shutter member constituted by a ball. The ball is intended to close an orifice through which the dispensing fluid passes whenever the receptacle is not in a normal position of use, and in which case actuating the valve might lead, for example, to propellant gas being lost. In the event of an attempt to use the device in the wrong position, the pressure downstream from the shutter member tends towards atmospheric pressure because of the communication with the outside that is established through the valve rod when the valve is actuated. The ball is then liable to remain pressed against its seat, even if the receptacle is turned back into the normal position of use, because the pressure inside the receptacle is greater than the pressure downstream from the shutter member.
In order to prevent the shutter member remaining for too long a time in its closing position, even after the receptacle has been put back in its normal position of use, a leak is provided for between the inside of the valve body downstream from the shutter member and the inside of the receptacle by means of a micro-orifice passing through the valve body.
Making such a micro-orifice turns out to be relatively difficult and complicates manufacture of the valve.
In addition, the valve has a gasket which is liable to become swollen in contact with the fluid contained in the receptacle, and swelling of this gasket tends to disturb the passage of propellant gas through the micro-orifice, thereby further complicating manufacture of the valve.
One object of the present invention is thus to provide a valve which makes it possible to avoid the shutter member being held in its closing position even after the receptacle has been turned over into a normal position of use, and that is relatively simple to implement while also being reliable.
This and other objects have now been realized by the invention of a valve for use in a pressurized receptacle containing a fluid to be dispensed therefrom with at least one propellant gas, the valve comprising a housing having an axis, an inner wall, and including an orifice for dispensing the fluid, a shutter member disposed in the housing, the shutter member movable along the axis under the action of gravity between a closed position in which the shutter member substantially closes the orifice when the valve is in a predetermined orientation and a dispensing position in which the shutter member releases the orifice, and an absorber disposed downstream from the shutter member relative to the direction of flow of the fluid, the absorber adapted to absorb the at least one propellant gas contained within the fluid and for releasing at least a portion of the at least one propellant gas upon a decrease in pressure in the area adjacent to the absorber. Preferably, the absorber comprises porous material.
In accordance with one embodiment of the valve of the present invention, the absorber comprises a material capable of absorbing the at least one propellant gas.
In accordance with another embodiment of the valve of the present invention, the absorber comprises polyamide fibers, preferably nylon fibers. In another embodiment, the absorber comprises a separate sintered member. In yet another embodiment, the absorber comprises silicone.
In accordance with another embodiment of the valve of the present invention, the housing comprises a valve body, and the valve includes a chamber in fluid communication with the valve body by means of the orifice, wherein the absorber is disposed in the chamber. Preferably, the absorber is affixed to the valve body.
In accordance with another embodiment of the valve of the present invention, the valve includes a valve rod, wherein the absorber is affixed to the valve rod. Preferably, the valve rod includes a first end, and the absorber is affixed to the first end of the valve rod.
In accordance with another embodiment of the valve of the present invention, the housing comprises a valve body, and the shutter member is disposed in the valve body.
In accordance with another embodiment of the valve of the present invention, the valve includes a dip tube affixed to the valve body, the shutter member being disposed in the dip tube.
In a preferred embodiment of the valve of the present invention, the shutter member comprises a ball.
In accordance with one embodiment of the valve of the present invention, the predetermined orientation comprises a head-down position for the valve, and the position for normal use of the valve comprises a head-up position for the valve. In another embodiment, however, the predetermined orientation comprises a head-up position for the valve and the position for normal use of the valve comprises a head-down position for the valve.
In accordance with another embodiment of the valve of the present invention, the valve includes actuation means for actuating the valve, the actuation means being actuated by being depressed. In another embodiment, the actuation means being actuated by being rocked.
In accordance with the present invention, a dispensing device has been discovered for dispensing a fluid comprising a pressurized receptacle containing the fluid and a valve as defined hereinabove.
In one embodiment, the present invention provides a valve for a pressured receptacle, the valve comprising:
an orifice configured to pass a fluid to be dispensed;
a shutter member movable under the action of gravity between a closing position taken when the valve has a predetermined orientation, in which closing position the shutter member substantially closes the orifice, and a dispensing position in which the shutter member releases the orifice; and
an absorber situated downstream from the shutter member relative to the direction of fluid flow, suitable for absorbing at least a propellant gas contained in the fluid and for releasing at least part of the propellant gas when the pressure in the vicinity of the absorber becomes low enough.
The shutter member is particularly configured in such a manner that the quantity of propellant gas that is released enables the pressure difference that exists across opposite sides of the shutter member to be reduced sufficiently for the shutter member to be able to leave its closing position in the event of the shutter member remaining in its closing position while no longer being held in its closing position by gravity.
The shutter member can leave its closing position on its own under gravity and/or under the action of movements of the receptacle.
The absorber may be made of a material and/or of a physical structure that are selected as a function of the nature of the substance(s) contained in the receptacle, in particular the nature of the propellant gas and the quantity of gas that is to be released by desorption, taking into account, for example, the configuration of the valve and the volume that the gas released by desorption is to occupy, the weight of the shutter member, the pressure that exists inside the receptacle, the shape of the shutter member, and the shape of its seat.
The absorber may comprise a porous material. The absorber may also comprise a material whose chemical nature enables it to absorb the propellant gas contained in the fluid. The absorber may be configured, for example, so as to be capable of absorbing a propellant gas selected from the group constituted by: alkanes, in particular butane, isopropane, and isobutane; fluorine-containing compounds, in particular difluoroethane 152a, and tetrafluoroethane 134a; and dimethyl ether, this list not being limiting.
The absorber may comprise fibers of polyamide, e.g. of nylon.
The absorber may comprise a cellular material, for example a foam or a sintered piece, in particular a sintered piece having high porosity with pores of a size that may lie, for example, in the range from about 5 microns (xcexcm) up to about 20 xcexcm.
The sintered piece may be constituted, for example, by a piece of sintered high density polyethylene, polypropylene, or polyvinylidene fluoride (PVDF).
The absorber may also comprise a silicone, in particular when the propellant gas is butane, isobutane, difluoroethane 152a, tetrafluoroethane 134a, dimethyl ether, or a mixture of at least two such compounds, because of the affinity that exists between silicone and the propellant gas.
The valve may comprise a valve body defining a chamber with which the above-mentioned orifice communicates, the chamber being situated downstream from the shutter member, and the absorber being disposed in the chamber. By way of example, the absorber may be fixed to the valve body. In a variant, or additionally, the absorber may be fixed to the valve rod. In particular, the absorber may be fixed to one end of the valve rod.
The shutter member may be disposed in a housing in the valve body. In a variant, the shutter member may be disposed in a dip tube fixed to the valve body.
The shutter member may comprise a ball, in particular a glass ball or a stainless steel ball.
The above-mentioned predetermined position which the shutter member occupies in its closing position may correspond to an attempt at using the valve in a head-down position. In that case, the receptacle is normally used in a head-up position in order to dispense the fluid contained inside. A dip tube may be fixed to the valve body.
The predetermined position in question may also correspond to an attempt at using the valve in a head-up position. In this case, the receptacle is normally used head-down. The valve need not have a dip tube.
The valve may be configured so as to be actuated by being depressed or rocked, for example.
The present invention also provides a device for packaging and dispensing a fluid, the device comprising:
a receptacle containing the fluid to be dispensed under pressure; an
a valve as defined above.